1. Field of the Invention
The present application is directed to a press for use with a continuously moving conveyor belt, such as, for example, a press for flattening dough pieces into tortillas on a moving conveyor belt.
2. Description of the Related Art
In the field of the manufacture of dough-based food products such as tortillas, a difficulty arises in the portion of the manufacturing process directed to pressing the dough into flat shapes. One cause of such a problem is that bread dough is somewhat elastic. Thus, pressing a ball of such dough into a flat pancake or tortilla-like shape requires a significant amount of work.
One type of device developed for pressing balls of dough into tortilla shapes is disclosed in U.S. Pat. No. 5,006,358 issued to Rubio, et al., Apr. 9, 1991. Such a press includes upper and lower platens which are mounted to a reciprocating frame. The frame is driven so as to reciprocate along a path that is parallel to the movement of the upper surface of a moving conveyor belt. As balls of dough are moved on the conveyor belt, between the platens, the reciprocating frame is moved at the same speed as the conveyor belt while the platens are pressed together, thereby flattening a plurality of balls of dough into tortilla shapes. The platens are then moved away from each other as they are slowed and returned back to a starting position. As such, the press can simultaneously flatten a plurality of pieces of dough without requiring the conveyor belt to stop.
The drive mechanism of the U.S. Pat. No. 5,006,358 patent for driving the platen support incorporates an electric motor, a drive belt driven by the motor, a gear reduction device having an rotating output shaft, and an oscillator drive. The oscillator drive includes gear configured to convert the rotating motion of the output shaft of the gear reduction device into an oscillating motion of a pivot arm. The pivot arm is connected to the reciprocating frame so as to move the press in the forward and backward directions.
Another type of system, disclosed in U.S. Pat. No. 5,388,503, issued to Buerkle, Feb. 14, 1995, uses a single electric motor driving both the conveyor belt and another mechanism for reciprocating the reciprocating frame. The system incorporates a number of gear reduction devices and chains or drive belts.
Other known systems have used hydraulic rams to reciprocate platen supports for pressing dough pieces into flat shapes. For example, British Patent No. 1,504,171 issued to Bibbe, et al., discloses a press for pressing dough pieces into piecrusts. The press is driven by a hydraulic ram forwards and backwards along the direction of the movement of a conveyor belt carrying the dough pieces.